Semiclassical theory of out-of-time-order correlators for low-dimensional classically chaotic systems

Abstract

The out-of-time-order correlator (OTOC), recently analyzed in several physical contexts, is studied for low-dimensional chaotic systems through semiclassical expansions and numerical simulations. The semiclassical expansion for the OTOC yields a leading-order contribution in ${\hslash }^2$ that is exponentially increasing with time within an intermediate, temperature-dependent, time-window. The growth-rate in such a regime is governed by the Lyapunov exponent of the underlying classical system and scales with the square-root of the temperature.

24 pages (one column), 7 figures. Some changes and corrections added. Closest to published version